Savestate: Reset what older states lack instead of keeping pre-load values

Missing sections (videocodec, audiocodec, aac, mp3) and old-version
branches (impose, io, umd, gps, mic, display, font) left the session
before the load in place.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Core/HLE/sceFont.cpp

@@ -1107,6 +1107,9 @@ void __FontDoState(PointerWrap &p) {
 
 	Do(p, actionPostAllocCallback);
 	__KernelRestoreActionType(actionPostAllocCallback, PostAllocCallback::Create);
+	if (s >= 2) {
+		useAllocCallbacks = true;
+	}
 	Do(p, actionPostOpenCallback);
 	__KernelRestoreActionType(actionPostOpenCallback, PostOpenCallback::Create);
 	if (s >= 2) {